Sensor intercalibration - adjustment of MODISNDVI- to NOAA-AVHRR-NDVI data

The Normalized Difference Vegetation Index (NDVI) is the most often used vegetation index to study environmental change. Usually, NOAA-Advanced Very High Resolution Radiometer (AVHRR)-data are used to calculate the NDVI, because these data are available for more than 20 years. Today, data with an improved quality like the one of EOS-Moderate Resolution Imaging Spectroradiometer (MODIS) are suitable for a continuation of the long-term AVHRR-NDVI data sets. Due to different sensor characteristics of MODIS and NOAA-AVHRR, the NDVI values vary according to the type of sensor. Therefore, an adjustment of the MODIS-NDVI is necessary, in order to make the data comparable to the AVHRR-NDVI. This work discusses such a new adjustment approach.